Toggling Subsystems

This is a common pattern that you might want to use on subsystems. Often, subsystems will have an on or off state, and you might want to toggle between them with a single button press. This may be advantageous for the driver, because it means they don't need to hold down a button to enable something.

PROSVEXCode

#include "main.h"

pros::Motor motor(1);
pros::Controller master();
pros::AdiDigitalOut piston();

bool move = false; // by default, this will not move
bool isPistonOn = false; // Piston starts retracted

void opcontrol() {
    while(true) {
        if(master.get_digital_new_press(pros::Digital_B)) {
            // If this is true, move will changed to false
            // and vice versa. 
            move = !move; 
        }

        // If move is true, move the motor.         
        if(move) {
            motor.move(100);
        }
        // Else, don't
        else {
            motor.move(0);
        }


        if(master.get_digital_new_press(pros::Digital_A)) {
            isPistonOn = !isPistonOn; 
        } 

        piston.set_value(isPistonOn);

        pros::delay(20);
    }
}

vex::motor mtr(vex::PORT1);

void Motor_Move() {
    mtr.spin(vex::directionType::fwd, 100);
}

bool prev_value = false; 
bool move = false;

int main() {
    // Since VEXCode doesn't have an equivalent function to 
    // get_digital_new_press, we need to detect the new push 
    // of a controller button. 
    while (1) {
        prev_value = Controller1.ButtonB.pressing();
        // Detect a new press
        if(prev_value == false && Controller1.ButtonB.pressing()) {
            move = !move;
        }

        if(move) {
            mtr.spin(vex::directionType::fwd, 100);
        }
        else {
            mtr.spin(vex::directionType::fwd, 0);
        }
        wait(20, msec);
    }
    // OR

    // Alternatively, VEXCode also supports 
    // callbacks bound to controller buttons
    //
    // DO NOT put this in a while loop, call before a
    // while loop unlike this example. 
    Controller1.ButtonB.pressed( Motor_Move );
}